A) Field of the Invention
This invention relates to a percussion instrument such as an electronic drum and a drum head of the percussion instrument.
B) Description of the Related Art
For example, as inventions of an electronic percussion instrument that can obtain the same striking feel as an acoustic drum and restrain a drum beat when stroked, there are inventions disclosed in Japanese Laid-Open Patent Hei 10-20854 (hereinafter called the patent document 1) and Japanese Laid-Open Patent 2001-142459 (hereinafter called the patent document 2). The electric percussion instrument detects a stroke on a drum head and electrically outputs sound corresponding to the detected stroke, for example.
In the electric percussion instrument disclosed in the patent document 1, a piezoelectric device for detecting a stroke on a drum head is adhered to a supporting part positioned inside the electric percussion instrument. A conic-trapezoidal cushion part formed of elastic material such as rubber or sponge is adhered to an upper surface of this piezoelectric device, and a tip of the cushion part contacts with the drum head. Since the cushion part contacts with the drum head, the stroke on the drum head is not directly transmitted to the piezoelectric device even if the drum head is stroked with a stick, and damage of the piezoelectric device can be suppressed.
Moreover, the electronic percussion instrument disclosed in the patent document 1 equips with a drum head formed of a netlike part made of a lamination of a first plain-woven net and a second plain-woven net wherein a weaving direction of each net is slanted to that of the another net as. In the disclosed percussion instrument, when the drum head is stroked with a stick, air passes through openings of a mesh of the netlike parts, and a drum beat produced by striking the drum head will be small.
On the other hand, the electronic percussion instrument disclosed in the patent document 2 equips with a drum dead made of a punching sheet having a large number of opening holes. In the disclosed percussion instrument, when the drum is stroke with a stick, transmission of vibration of the drum head to the air is decreased by the large number of the opening holes, and the drum beat will be small. Also, since rebounding of the stick on the punching sheet is larger than that on the netlike drum head, a striking feel like a normal acoustic drum can be obtained.
When the instrument is shaped by imitating an acoustic drum such as the electric percussion instrument disclosed in the patent document 1, parts other than the drum head may be touched with a stick or by a performer. In the electric percussion instrument disclosed in the patent document 1, the supporting material adhered to the piezoelectric device is fixed to a body of the electric percussion instrument. Therefore, when the stick or a performer touches with a part other than the drum head, the vibration by the touch is directly picked up by the piezoelectric device adhered to the supporting part. When the vibration is transmitted to the piezoelectric device, the piezoelectric device detects the vibration, and a sound corresponding to the touch will be output without striking on the drum head.
Moreover, because the drum head is a nondurable part, it is necessary to also have durability in some extent. In order to improve durability of the drum head in the percussion instrument disclosed in the patent document 1, it is considered that intervals of the plain woven fibers is made to be close. However, when the intervals of the fibers are close, opening parts become narrow, and silencing ability will be degraded. In order to improve durability of the drum head in the electronic musical instrument disclosed in the patent document 2, it is considered that thickness of the punching sheet is made to be thickened. However, when the punching sheet is thickened, tension of the drum head stretched over the body (sound box) becomes high, going down of a tip of the stick to the drum head will be small. Therefore, the striking feel will be the same as that when striking a board and a good striking feel cannot be obtained.